User consent and third-party applications

Heads up! As part of our efforts to improve security and standards-based interoperability, we have implemented several new features in our authentication flows and made changes to existing ones. For an overview of these changes, and details on how you adopt them, refer to Introducing OIDC Conformant Authentication.

The OIDC-conformant authentication pipeline supports defining resource servers (such as APIs) as entities separate from applications. This lets you decouple APIs from the applications that consume them, and also lets you define third-party applications that you might not control or even fully trust.

Types of applications

All Auth0 applications are either first-party or third-party.

First-party applications are those controlled by the same organization or person that owns the Auth0 domain. For example, suppose you wanted to access the Contoso API; in this case, there would likely be a first-party application used for logging in at contoso.com.

Third-party applications are controlled by different people or organizations who most likely should not have administrative access to your Auth0 domain. They enable external parties or partners to access protected resources at your API in a secure way. A practical application of third-party applications is the creation of "developer centers", which allow users to obtain credentials in order to integrate their applications with your API. Similar functionality is provided by well-known APIs such as Facebook, Twitter, GitHub, and many others.

Creating a third-party application

All applications created from the management dashboard are assumed to be first-party by default.

At the time of writing, third-party applications cannot be created from the management dashboard. They must be created through the management API, by setting is_first_party: false.

All applications created through Dynamic Client Registration will be third-party.

If a user is authenticating through a third-party application and is requesting authorization to access the user's information or perform some action at an API on their behalf, they will see a consent dialog. For example:

GET /authorize?
client_id=some_third_party_client
&redirect_uri=https://fabrikam.com/contoso_social
&response_type=token id_token
&scope=openid profile email read:posts write:posts
&audience=https://social.contoso.com
&nonce=...
&state=...
Auth0 consent dialog - Fabrikam Application for Contoso is requesting access to your account

If the user chooses to allow the application, this will create a user grant which represents this user's consent to this combination of application, resource server and scopes.

The application will then receive a successful authentication response from Auth0 as usual.

Once consent has been given, the user will no longer see the consent dialog on subsequent logins.

Handling rejected permissions

If a user decides to reject consent to the application, they will be redirected to the redirect_uri specified in the request with an access_denied error:

HTTP/1.1 302 Found
Location: https://fabrikam.com/contoso_social#
    error=access_denied
    &state=...

Only first-party applications can skip the consent dialog, assuming the resource server they are trying to access on behalf of the user has the "Allow Skipping User Consent" option enabled.

Consent can't be skipped on localhost

Note that this option only allows verifiable first-party applications to skip consent at the moment. As localhost is never a verifiable first-party (because any malicious application may run on localhost for a user), Auth0 will always display the consent dialog for applications running on localhost regardless of whether they are marked as first-party applications. During development, you can work around this by modifying your /etc/hosts file to add an entry such as the following:

127.0.0.1       myapp.example

Once you do this, remember to update your application configuration URLs, such as the Allowed Callback URLs (found in Dashboard > Applications > Settings), and the callback URL you configured in your application, to match the updated domain-mapping.

Since third-party applications are assumed to be untrusted, they are not able to skip consent dialogs.

If a user has provided consent, but you would like to revoke it, you can do so via Dashboard > Users. Select the user in which you are interested, and switch over to the Authorized Applications tab.

Click Revoke next to the appropriate application.

Password-based flows

When performing a Resource Owner Password Credentials exchange, there is no consent dialog involved. During a password exchange, the user provides their password to the application directly, which is equivalent to granting the application full access to the user's account.

When redirecting to /authorize, the prompt=consent parameter will force users to provide consent, even if they have an existing user grant for that application and requested scopes.

As of today the consent dialog UI cannot be customized or set to a custom domain. We plan to implement this in future releases.